<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style type="text/css">
        *{
            margin: 0;
            padding: 0;
        }
        div.daohang{
            width: 100%;
            height: 50px;
            background-color: rgb(51, 51, 202);
        }
        div.yejiao{
            margin-top: 5px;
        }
        div.main{
            width: 80%;
            height: 800px;
            background-color: chocolate;
            float: right;
            margin-top: 5px;
        
        }
        div.cebianlan{
            width:19.5%;
            height:800px;
            background-color: darkcyan;
            margin-top: 5px;
        }

        
    </style>
</head>
<body>
    <div class="daohang">
    </div>
    <div class="main"></div>
    <div class="cebianlan"></div>
    <div class="daohang yejiao">hello</div>
</body>
</html>